1. Field of the Invention
The present invention relates to photographic processing equipment. In particular, the present invention is an improved print stacking apparatus for stacking individually cut photographic prints.
2. Description of the Prior Art
In commercial photographic processing operations, very high rates of processing need to be achieved and maintained in order to operate profitably. To expedite the photographic processing, orders containing film of similar type and size are spliced together for developing. As many as 500 to 1000 rolls of 12, 20, 24 and 36 exposure film may be spliced together for processing and printing purposes.
After developing, the photographic film contained in the film negatives are printed in an edge-to-edge relationship on a continuous strip of photosensitive paper by a photographic printer. The photographic printer causes high intensity light to be passed through a negative and imaged on the photographic print paper. The photographic emulsion layer on the print paper is exposed and is subsequently processed to produce a print of the image contained in the negative.
After the strip of photographic print paper has been processed to produce prints, a photographic paper cutter cuts individual prints from the strip. The prints are then sorted by customer order, either manually or automatically, and ultimately packaged and sent to the customer.
Automatic print paper cutters have been developed which automatically cut the print paper into individual prints. These automatic paper cutters are controlled by indicia which are placed along the print paper by the photographic printer. Typically the indicia are of two types: cut marks and end-of-order marks. Cut marks indicate the desired location of a cut between adjacent prints. End-of-order marks, which typically appear along the opposite edge of the print paper from the cut marks, indicate the end of a customer's order. The automatic paper cutter includes a sensor which senses the cut marks and causes the individual prints to be cut from the strip at desired locations. The separated prints are passed to an order packaging or grouping device which groups the prints in response to the end-of-order marks which are sensed by the automatic cutter.
The desire for higher rates of processing within commercial photographic processing operations has led to the development of extremely high speed automatic paper cutters. One example of such an automatic paper cutter is described in U.S. Pat. No. 4,128,887 by G. Strunc and F. Laciak, which is assigned to the same assignee as the present application. The automatic paper cutter described in this patent is capable of cutting over 25,000 prints per hour (i.e. over seven prints per second).
Print stacking devices have been developed for stacking the photographic prints which have been cut by the photographic paper cutter. In some cases, these print stacking devices have been an attachment or addition to a photographic paper cutter, while in other cases the print stacking device has been part of an automatic print sorter. In general, these prior art print stacking devices have included means for conveying the photographic print from the paper cutter and depositing the print into an open box or container. The prints are deposited generally one on top of the other to form the stack of prints.
These prior art print stacking devices, however, have not been entirely successful. It has proved difficult to produce a print stacking device which yields uniform stacks of prints which can be quickly and easily handled. Instead, the operator has often been required to rearrange the prints, such as by standing a stack of prints on edge on a flat surface and tapping the prints to align their edges prior to insertion of the prints into a pocket of the customer order envelope. This procedure, of course, is time-consuming and reduces the overall efficiency of handling the photographic prints.
One particularly advantageous print stacking device is shown in U.S. patent application Ser. No. 21,091 filed Mar. 16, 1979 by Robert E. Diesch and Charles L. Eutenuer, which is assigned to the same assignee as the present application. In this device, upper and lower print receiving elements are positioned proximate the discharge end of a conveyor system which conveys photographic prints from a photographic print cutter. The upper print receiving element is preferably a floating foot element. The lower print receiving element, which is preferably a print supporting platform, is movable generally downward and away from the upper print receiving element as the prints are deposited on the lower print receiving element. The conveyor system delivers the prints with sufficient force to carry the prints between the upper and lower print receiving elements until their leading edges engage a stop element which is preferably connected to a base element located below the lower print receiving element.